Opposed cylinder two-cycle engine



2 Sheets-Shut 1 Filed Sept. 26, 1945 vll..

Patented July 20, 1948 UNITED y STATES PATENT OFFICE- I GPPOSED CYLINDER TWO-CYCLE ENGINE John S. Wenzel, Manchester, Conn., asslgnor to Wenzel, Wenzel, Maoquire &

partnership Richardson, a s

Application September 26, 1945, Serial No. 618,684

This invention relates to engines and more particularly to internal combustion engines of the lever type. l

One of the objects of the invention is to provide an engine which will deliver an extremely high torque at a light weight per horse-power.

Another object is to provide an enginewhich is simple in construction which provides a mini- 'mum number of parts and which occupies a minimum volume.

Still another object is to provide an engine which operates at extremely high efficiency. This is accomplished by providing a relatively long ing or housing III which may, if desired,- contain a body of lubricant and" which serves as the crankcase of the engine. Secured to the central casing and projecting outwardly from the opposite sides thereof are aligned opposed pistons I I which are arranged in pairs. As shown in Figures 2 and 3, two such pairs of cylinders are provided, although it will be apparent that any desired number of cylinders could be employed.

'I'he engine, as shown. is adapted to operate on a two stroke cycle and for this purpose the outer end of each cylinder is connected to an intake passage I2 communicating with a source of com-` bustible mixture under pressure. the mixture to the cylinder is controlled by an intake valve ilgof the poppet type urged toward its seat by a spring I4. The valves I3 are adapted to be opened by rocker arms I5 engaging the outer ends of the valve stems and controlled by push rods i6 in a manner to be described hereinafter. Exhaust of combusted mixture from the cylinders is through exhaust passages I1 communicating with the cylinders through elongated exhaust ports Iladjacent the inner ends of the cylinders. A piston I3 isslidable in each cylinder and is formed with an elongated skirt which will close the exhaust ports Il when the cylinderv is in its extreme outer position. V

Within the casing il there is provided a rocking lever 2l for each pair of cylinders. The outermost lever 2| is connected to ashaft 22 displaced Admission ofY 1 claims. (ci. 12s-5s) sponding lpair of cylinders II and is connected to4 the pistons in such cylinders by connecting rods 23. The nearest adjacent lever 2i is secured to a sleeve 24 which is rotatable on the shaft 22 and has its free end lying between its pair of cylinders and similarly connected to the pistons therein. Where additional pairs of cylinders are employed, additional sleeves similar to the sleeve 24 may be provided to carry levers for such pairs of cylinders.

The shaft 22 and the sleeve 24 extend beyond the casing I li into an extension thereof indicated at 25. Within the casing extension 25 the sleeve and the shaft carry crankarms 28 which are connected through connecting rods 21 to oppositely disposed crank throws 28' on a crankshaft `23. Thecrankshaft 28 extends parallel to the shaft 22 through the upper part of the casing I0 and the casing extension 25 and may be connected to any desired mechanism to be driven.

To control the valves I3, the crankshaft is formed with cams 29, there being one cam for each pair of cylinders. Each of the cams 20 0perates on a pair of cam follower blocks 3l connected to the push rods I3. As best seen in Figure l, the cams 29 are single lobe cams so that each of the valves I3 of a pair of cylinders will be opened once during each revolution of thev crankshaft. l

In operation of the engine with the crankshaft turning in the direction of the arrow in Figure 1, the intake valve of the right-hand cylinder is open and the exhaust ports I8 are also open. At

this time a fresh charge under pressure enters the right-hand cylinder to scavenge the combusted charge from the cylinder and tcrrecharge it. At the same time a charge in the left-hand cylinder is being compressed and will be fired as, for example. by a spark plug 32 when the cylinder reaches the outer end of its stroke. This explosion will drive both pistons to the right and will rock the lever 2|l connected thereto to turn the shaft 22 and to rotate the crankshaft through the connecting rod 21. As the pistons travel to the right the charge in the right-hand cylinder will be compressed while 4that in the left-hand cylinder is burning and expanding as will be understood.

It will be noted that during this operation the inertia of the pistons and the lever connected thereto is dissipated in compressing the charge laterally from the axis of the cylinders and exin the freshly charged cylinder so that at the end of the working stroke the parts will come gradually to rest preparatory to a reversal of motionl whenv the charge in the opposite cylinder is fired. l

Thus, substantially all of the energy imparted to the engine is utilized in useful work to produce an emciently operating engine.

The eiliciency is further improved by providing an extremely long stroke for the pistons which is permissible due to absorption of the inertia forces. It will be seen that the stroke of the pistons is extremely long relative to .their diameter so that the burning charge can be substantially fully expanded prior to opening ofthe exhaust ports. By this means, the maximum useful energy in the charge is extracted therefrom.

Due to the arrangement of the cylinders in opposed pairs it is possible to obtain a well balanced and smooth running engine by simultaneously firing cylinders on opposite sides of the engine. `For example, in a four cylinder engine as shown. the cylinder of one pair on the left side of the engine fires at the same time as the cylinder of the other pair on the right side of the engine. In this way the forces are maintained in balance so that the engine runs smoothly at all speeds.

While one embodiment of the invention has been shown and described in detail herein, it will be understood that this is illustrative only, and is not intended as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. An engine comprising a pair 'of opposed cylders, pistons in the cylinders, valves to control supply of a combustible mixture to the outer ends of the cylinders, exhaust means communicating with the cylinders adjacent their inner ends whereby the pistons operate on a two stroke cycle, a lever pivoted on an axis displaced laterally from the cylinders with its free end lying -between the inner ends of the cylinders, connecting rods connecting the pistons to the free end of the lever, a crankshaft, means including a connecting rod connecting the lever to the crankshaft to rotate the crankshaft as the lever is oscillated, Aa cam on the crankshaft, and means operated by the cam to control the valves.

2. An engine comprising a central casing, cylinders opening into the casing and extending therefrom in opposite directions, pistons in the cylinders, a lever pivoted vin the casing on an axis spaced laterally from the cylinders with its free end lying between the cylinders, connecting rods connecting the pistons to the free end of the lever, a crankshaft extending through the casing, means connecting the lever to the crankshaft to rotate the crankshaft as the lever oscillates, a c'am on the crankshaft in the casing. and valves in the cylinders operatively connected to the cam to be controlled thereby.

3. An engine comprising a. central casing, cylinders opening into the casing and extending therefrom in opposite directions, pistons in the cylinders, a lever pivoted in the casing on an axis spaced laterally from the cylinders with its free end lying between lthe cylinders, connecting rods connecting the pistons to the free end of the lever, a crankshaft, means connecting the lever to the crankshaft to rotate the crankshaft as the lever oscillates, a cam on the crankshaft, valves in the outer ends of the cylinders controlled by the cam, and exhaust means communicating with the cylinders adjacent their inner ends whereby the pistons operate on a two stroke cycle.

4. An engine comprising a central casing, cylinders opening into the casing vand extending ing spaced laterally from the cylinders and extending transverse to the cylinder axes, a lever carried by the shaft with its free end between the inner ends of the cylinders, connecting rods connecting the pistons to the free end of the lever, mixture inlet valves in the outer ends of the cylinders, exhaust means communicating with the cylinders adjacent their inner ends whereby the engine operates on a two stroke cycle, a crankshaft, a crank arm on the crankshaft. a connecting rod connecting the crank arm and the lever, and a cam on the crankshaft controlling the mixture inlet valves.

5. An engine comprising a central casing, a plurality of pairs of opposed cylinders opening into the casing, pistons in the cylinders, a lever pivoted in the casing for each pair of cylinders with its free end lying between the cylinders, connecting rods connecting the pistons to the levers respectively. a crankshaft having a number of crank throws equal to .the number of levers, a shaft connected to one of the levers, a sleeve rotatable on the shaft connected to another of the levers, crank arms on the shaft and sleeve, and connecting rods connecting the crank arms and crank throws respectively.

6. An engine comprising a central casing, a plurality of pairs of opposed cylinders opening into the casing, pistons in the cylinders. a lever pivoted in the casing for each pair of cylinders with its free end lying between the cylinders, connecting rods connecting the pistons to the levers respectively, a crankshaft having a number of crank throws equal to the number of levers, means connecting the levers respectively to the crank throws, a cam on the crankshaft for each pair of cylinders, valves in the outer ends of the cylinders controlled -by the cams respectively, and exhaust means communicating with the cylinders adjacent their inner ends whereby the engine operates on a two stroke cycle.

1 7. An engine comprising a central casing. s

air of opposed cylinders opening into thecasing lwhich are long relative to their diameters, inlet valves at the outer ends of the cylinders, exhaust means communicating with the cylinders adjacent their inner ends. pistons in the cylinders having skirts of a length to -cover the exhaust means when the pistons are in their outermost positions, a lever pivoted in the casing on an axis spaced from the cylinders with its free end lying between the cylinders, connecting rods connecting the pistons to the free end of the lever, a crankshaft, means connecting the lever to the lcrankshaft to turn it as the lever oscillates, and al cam on thev crankshaft controlling the inlet valves.

Number JOHN S. WENZEL. REFERENCES CITED UNITED STATES PATENTS Name Date Heermans Sept, 8, 1908 Gerling May 10, 1932 Weidner Jan. 3, 1933 Bogert Dec. l2. 1933 Wormsley Sept. 17, 1940 Hawkins Aug. 28, 1946 

